Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
van thanh » ban thanh, van tuan
nang dai » nang dau, nang tai, lang dai
tu sach » thu sach, su sach, te sach
cac xuc » cac nuoc, chat xuc, cac cuoc
dai hoi » dai hoc, dai hai, dai moi
y nang » ky nang, ly nang, v nang
vi hoa » voi hoa, va hoa, bi hoa
vi hoc » li hoc, va hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang dai hoi. hieu hien ((cac xuc) or (cam xuc)) van thanh ((vi hoa) OR (vi hoc)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang dai hoi. hieu hien ((cac xuc) OR (cam xuc)) van thanh ((vi hoa) OR (vi hoc)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang dai hoi. hieu hien ((cac xuc) or (cam xuc)) van thanh ((vi hoa) OR (vi hoc)) viet".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang dai hoi. hieu hien ((cac xuc) or (cam xuc)) van thanh ((vi hoa) OR (vi hoc)) viet*.